This invention relates to a method and apparatus for attaching a sealing piece onto a pour-out hole of a plastic closure cap or a plastic container.
It has been proposed to attach a sealing piece onto a pour-out hole of a closure cap or a container in order to prove that a material in the container has not been used at all after filling thereof until delivered to a user. The attaching of the sealing piece has been made by holding the molded plastic container or closure cap in an upright position, placing the sealing piece upon the pour-out hole of the container or closure cap, and subjecting it to heat sealing orultrasonic sealing.
However, such sealing technique requires a precise positioning of the container or closure cap to a predetermined position, which makes an automatic sealing machine complicated and expensive. Also, it is required to accurately control the sealing conditions such as sealing time period, temperature and pressure to avoid weak sealing and excessive sealing. Especially, when the sealing piece has to be attached lightly onto the pour-out hole of the container or closure cap so as to be peeled off, such sealing conditions become critical with accurate control of the various factors for sealing.
Accordingly, an object of the present invention is to provide a method and apparatus for attaching a sealing piece onto a pour-out hole of a plastic closure cap or a plastic container very easily without using a special device for holding and positioning after molding thereof.
Another object of the present invention is to provide a method and apparatus for removably attaching a sealing piece onto a pour-out hole of a plastic closure cap or a plastic container without high accuracy of sealing conditions such as required in the conventional sealing technique.